function preview(oper) {
    if (oper < 10){
        bdhtml=window.document.body.innerHTML;//获取当前页的html代码
        sprnstr="<!--startprint"+oper+"-->";//设置打印开始区域
        eprnstr="<!--endprint"+oper+"-->";//设置打印结束区域
        prnhtml=bdhtml.substring(bdhtml.indexOf(sprnstr)+18); //从开始代码向后取html
        prnhtml=prnhtml.substring(0,prnhtml.indexOf(eprnstr));//从结束代码向前取html
        window.document.body.innerHTML=prnhtml;
        window.print();
        window.document.body.innerHTML=bdhtml;
        parent.layer.close(parent.layer.getFrameIndex(window.name))
    } else {
        window.print();
        parent.layer.close(parent.layer.getFrameIndex(window.name))
    }
}